Joshua nobbish



Aug. 25, 1925 1,551,424

' J. NORRISH ROASTING FURNACE Filed Sept. 26,- 1922- I 242/922 for Jbs/zua )Vorris/z fliorne ys Patented Aug. 25, 1925.

UNITED STATES JOSHUA NORBISH, OF SAN FRANCISCO, CALIFORNIA.

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Aiiplication filed September 26, 1922. Serial No. 590,714.

To all whom it may concern:

Be it knownthat I, JOSHUA NORRISH, a citizen of the United States, residing at the city and county of San Francisco and State of California, have invented new and.useful 1m rovements in Roasting Furnaces, of

which the following is a specification.

This invention relates to a roasting furnace, and especially to a vertical shaft type of furnace employing a gravity feed.

The object of the present invention is to generally improve and simplify roasting furnaces of the stack type; to provide a furnace which is adapted for roasting and desulphurizing ores, and also for retorting such products as oil shale and the like; to provide a furnace which is continuous in operation and in which the material is fed by gravity from-the point of intake to the point of discharge and maintained under constant movement and agitation throughout the entire roasting operation; and further to rovide a novel arrangement of electric eating elements whereby heat may be directly and efliciently applied to the ore or other material being treated. Other objects will hereinafter appear.

One form which my invention may assume is exemplified in the following descri tion and illustrated in the accompanying rawin?, in which ig. 1 is a central, vertical, longitudinal section through the furnace.

Fig. 2 is a cross section on line 2-2, Fig. 1.

Fig. 3 is a perspective view of one of the baflle supports.

Fig. 4 is a perspective view of the uppermost bafiie member.

The furnace as shown in Figs. 1 and 2 is a so called stack furnace. It is circular in cross section. It consists of an outer wall constructed of common brick and an inner wall constructed of metal or a refractory material as desired. The interior or roasting chamber formed is also cylindrical in cross section, and dis sed therein are two u right members as indicated at '2 and 3.

ese members extend from the top to the bottom of the furnace and will hereinafter be referred-to as baifle supports. Both members are identical in construction and they are particularly illustrated in a perspective view, see Fig. 4. Each baflle sup rt is provided with a series of an lar y disposed supporting shelves 4, whic are staggered with relation to each other, see Fig. l, and

disposed intermediate these shelves is a series of hollow baffle member or plates, such as indicated atB. These bathe plates are identical in construction and are disposed in opposition to each other to form a tortuous inclined passageway through which the ore is fed by gravity during the roasting operation. Each baflie member, (see Fig. 4,) consists of a bottom section 7, a top section 7 side sections 8, and an end section 9. The side sections are bevelled off at one end, as indicated at 10, and as such form supports for one end of the succeeding bathe member. The bottom section of each bafile is provided with a. discharge opening, as shown at 11, through which the ore or material being treated discharges from one baflle member to;another. The bafiies, together with the members 2 and 3, supporting the same, are removable and a demountable iron dome 12 is therefore employed. This dome may be covered with a refractory material as desired, and is secured by anchor bolts, as indicated at 13. This construction is im portant as it permits the furnace to be opened from time to time for inspection, repairs or otherwise, and broken bafile plates or heating elements hereinafter to be referred to may therefore be quickly an easily reached when desired. I

The furnace here illustrated is particularly adapted for roasting'ores such as cinnabar, zinc ores and the like. It may also be employed for desulphurizing ores, and it may furthermore be applied as a retort when handling oil shales and similar products. The furnace is continuous in operation; the ore being delivered to the uppermost baffle through a hopper not shown through a pipe 14. The ore deposited on the inclined bottom section ofthe uppermost bafile runs by gravity down to the dis charge opening 11 and it is then deposited on the second battle. This is inclined in the opposite direction and the ore will therefore travel in a tortuous path from the top to the bottom before it-can discharge. The heat is supplied to the furnace by means of electricity, that is four vertically disposed electric ribbon heating units are employed asindicated at 15, 16, 17 and 18. Theseribbons extend from end to end of the furnace and supply the heat whereby the interior of the furnace chamber is raised to any temperature desired, and whereby heat is imparted to the baffle members B, over and through which the ore passes. The fumes liberated during the roasting of the ore pass upwardly and discharge through a pipe 19, which leads to a condenser of suitable construction not here shown. The ore when roasted discharges from the lowermost batlle and passes out through the discharge opening indicated at 20, a sliding gate 21 being here employed as a closure whenever required. The discharging material may be delivered to a conveyor not here illustrated and may in this manner he removed from the furnace to any point of discharge desired.

The ribbon elements indicated at 15, 16, 17 and 18, are supported by terminal posts as indicated at 22. These posts extend through the walls of the furnace and are insulated therefrom in the usual manner. They are otherwise connected with a suitable source of current supply.

The present invention has numerous advantages when comparison is made with types of similar construction. First of all it will be noted that all parts exposed to high temperature are stationary and as such may be constructed of refractory material, which can withstand high temperatures when required. The baflle members employed are all disposed on an incline, thus permitting a gravity feed, this being of particular importance as it eliminates all mechanical feeding devices usually em ployed and which are readily destroyed by high furnace temperatures. By increasing and (lecreasingthe incline of the battles, the time element required when roasting ore in particular may be changed, and as the ore is maintained under constant movement and is agitated when it drops from shelf to shelf, it can readily be seen that all ore particles will be exposed to the heat of the furnace and thereby uniformly acted upon. The cost of operating a furnace of this character should be comparatively small as the heat is electrically applied and as such does not require air drafts which carry away a great portion of the heat. Itis furthermore obvious that a furnace of this character can be efficiently insulated against heat losses and as such should increase the general efliciency of the same. The interior construction of the furnace is such that accessibility for inspection and repairs is permissible by merely removing the dome l2, and as practically all parts employed in the interior construction are identical in size, shape, spare parts may be maintained.

The inner end of the feed pipe indicated at 14 is perforated as shown to permit escape of gases which might form. Other minor details of construction may be resorted to within the scope of the appended claims. I similarly wish it understood that the materials and finish of the several parts employed may be such as the experience and judgment of the manufacturer may dictate or various uses may demand.

In instances Where sulphur is encountered and where the ore or material treated contains moisture, it is obvious that metal objects would be detrimentally affected by the sulphurous fumes produced. In cases of this character it is desirable to isolate the heating ribbons 15, 16, 17 and 18, or in other words to prevent the fumes from reaching the same. This is accomplished by cementing or otherwise joining the baflie members where they connect to prevent escape of gas,

and also by enclosing the same from top to bottom betweenthe members 2 and 3 in a pair of side plates 31 and 32, which also extend from the top to the bottom of the furnace. The plates 31 and 32, together with the plates 2 and 3, form a rectangular passage from the top to the bottom of the furnace, interior of which the baffle members B are mounted. This rectangular passage, together with the baflle members, is gas tight and communicates with the discharge pipe 19 at one end and with the discharge opening 20 at the opposite end. The heating elements referred to are thus protected.

Having thus described my invention, WhatI claim and desire to secure by Letters Patent is- 1. In a furnace of the character described having a vertical cylindrical roasting chamber, vertical Walls arranged within the roasting chamber and forming a rectangular passage and fitted at their corners against the walls of the cylindrical roasting chamber and forming intervening spaces for the reception of heating elements and a series of oppositely inclined bafile plates arranged Within the rectangular passage and formin a tortuous passage through which the material to be roasted may flow by gravity from the upper to the lower end of the roasting chamber.

2. In a furnace of the character described having a vertical roasting chamber, vertical walls arranged within the roasting chamber and forming a rectangular assage and oppositely inclined hollow hu e members fit.- ted together and mounted within the rectangular passage and forming interiorly of them a tortuous passage through which the material to be roasted may flow by gravity from the upper to the lower end of the roasting chamber.

3. In a furnace of the character described having a vertical roasting chamber, vertical metallic walls arranged within the roasting chamber and forming a rectangular passage, two of the opposite walls being r0- vided with supportin shelves arrange in staggered relation, anfa series of 0 positely inclined hollow bafile members fi tted togeth'er and supported upon the said shelves and forming interiorly of the said baffle members a tortuous path down which the materialto be roasted may flow by gravity from the upper to the lower end of the roasting chamber. A

4. In a furnace of the character described having a vertical roasting'chamber four ver tical walls within the roasting chamber and forming a rectangular assage and oppor sitely inclined tapering ollow bafile members fitted together at their ends and provided thereat with communicated openin s and forming a tortuous passage. interior y of the baflle members through which the material to be roasted may flow fromythe upper to the lower end of the roasting chamber.

:5. In a furnace of the character described having a vertical cylindrical roasting chamher, four vertical walls arranged within the roasting chamber and forming a rectangular passage and contacting at their corners with the walls of the cylindrical roasting chamber and forming intervening spaces for the reception of heating means, two of the 0pposite walls being provided at intervals with shelves, the'shelves of one wall bein staggered with relation to the shelves of t e opposite wall, and hollow oppositeg inclined tapering baflle members sup rte upon the said shelves and fitted toget er at their adjacent ends and provided thereat with com municating openings and forming a tortuous passa e t be waste may ow by gravit from the upper to the lower end of t e roasting chamber.

JOSHUA NORRISH.

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